Interpretive Summary: As food composition values change over time, it is not always apparent whether these changes are the result of actual changes in foods, such as meats with lower fat content, or the result of an improved analytical database. However, classification of these changes is necessary for the accurate comparison of current nutrient intake estimates with estimates generated in earlier years. The multi-year Food and Nutrient Database for Dietary Studies (multi-year FNDDS) is designed to track changes in foods and facilitate analysis of intake trends in the United States. It contains 14,500 food descriptions, 32,000 weights for common food portions, and up to 61 nutrients/food components for each food. It categorizes real changes in the U.S. food supply vs. data improvements; improved values replace the older values, whereas multiple records are present where foods have changed over time. Researchers can use the database for many research projects including reanalyzing food intake data collected in earlier years, taking advantage of the improved data, but maintaining the integrity of food values for the original time period in research projects using food intake data from nationwide surveys, and to investigate the real differences in nutrient intakes between surveys in comparative studies, and accurately track changes in intakes over time.

Technical Abstract:
The multi-year USDA Food and Nutrient Database for Dietary Studies (FNDDS) is a database of foods, their nutrient values, and weights for typical food portions. It contains about 14,500 food descriptions, 32,000 weights for common food portions, and up to 61 nutrients/food components for each food. It represents data for years 1994-2002 and is designed to track changes in foods and facilitate analysis of intake trends. It categorizes real changes in the U.S. food supply vs. data improvements; improved values replace the older values, whereas new data representing real changes in foods are time stamped. The database is now available in MS Access format on a CD-Rom for researchers. Researchers can use this resource for reanalyzing food intake data collected in earlier years, taking advantage of the improved data, but maintaining the integrity of food values for the original time period; in research projects using food intake data from nationwide surveys - Continuing Survey of Food Intakes by Individuals (CSFII) 1994-96, 1998, the National Health and Nutrition Examination Survey (NHANES) 1999-2000, and What We Eat In America/NHANES 2001-2002, to investigate the real differences in nutrient intakes between surveys in comparative studies, and to accurately track changes in intakes over time. Extensive documentation and a user guide accompany the release.